Yes! I see a bunch of wagons there's!
Lawn chairs, yes! People bring chairs and small sunshades all the time. Wagons, I'm not sure, but not up to the top of the slides (you'd have to walk back up to retrieve them.)
People used rolling coolers and HUGE beach bags, but I do not recollect people pulling wagons. The limitation is the tight width at the entryway of the park. A double wide stroller barely fit through the entryway.
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